Ok my car has a problem with idling. When the car is in PARK it will run at around 750rpm then jump to 2000 and hang for a minute and then back down to 750. When in DRIVE it hovers around 500 or 600 and is on the verge of dying. Sometimes it will die sometimes it won't. I drove it to tafel motors and they looked at it and determined it had a bad vacuum leak. Later in the day the said the total to fix would be $1400.00. They said that not only is there a vacuum leak but the Air flow housing is bad. The mechanic said the sensor is not giving a correct reading. The part is 800, although I found it on benzbin for 550. He said that should clear the problem up. Does that sound about right??? Also now the car won't run hardly at all though. I not sure if putting the new vacuum lines on did something. It was the vacuum lines right by the air flow housing.

What do you guys think?

Thanks